It is common to use spray guns for applying primer, paint, varnishes, stains, and for other similar surface finishing products. Such spray gun devices routinely use pressurized air, discharged to and through the gun, into a container filled with the product to be applied, e.g. paint. The pressurized air forces the product through the nozzle of the spray gun for application.
However, when a particular job is finished or the type of applied product must be changed, e.g. using a different color paint, it is necessary that the internals of the spray gun be thoroughly cleaned. This ensures for its maintenance and extended work life, and provides that it will be in good condition for reuse. Moreover, there is nothing more frustrating to the user than having a solidified piece of the prior paint or other fluid residue break free from inside the gun, discharge through the nozzle, and spoil the finish of the work in progress.
There have been a number of prior attempts to clean spray guns. For instance, a common practice is to immerse a spray gun in a solvent or paint thinner. However, while some of the paint or fluid will be dislodged, much of it, especially inside the spray gun, will not. Some cleaning systems circulate solvent or other cleaning fluid through spray guns. Examples of such systems are found in U.S. Pat. Nos. 1,816,555, 4,746,063, and 5,855,218. However, the systems disclosed in these and other prior art have a number of significant disadvantages. For instance, such systems often are only designed to circulate solvent or cleaning fluid one time through the spray gun and then to discharge it into a separate receiving container. This has the obvious disadvantage of being an inefficient and wasteful use of cleaning fluid. There is also the burden of providing a separate recirculating system in which the cleaning fluid must be collected and then disposed of after the single pass. Given this limited circulation of cleaning fluid, such systems fail to completely clean the spray gun. Prior systems also must be constantly re-actuated and attended to by the user during the cleaning procedure. Significantly, none of the prior art systems automatically and continuously, without any user intervention, re-circulates cleaning fluid within a spray gun, to clean it thoroughly and completely.
It is thus an object of the present invention to provide a spray gun cleaning system which addresses these disadvantages and limitations of prior spray gun cleaning systems.
It is an object of the present invention to provide a spray gun cleaning system which thoroughly and completely cleans the internal surfaces of a spray gun.
It is a further object of the present invention to provide a spray gun cleaning system which efficiently and effectively cleans a spray gun with minimal user involvement.
It is another object of the present invention to provide a spray gun cleaning system which uses a minimal amount of solvent or other cleaning fluid to thoroughly clean a spray gun.
It is still another object of the present invention to provide a spray gun cleaning system which re-circulates solvent or other cleaning fluid for continuous flow through a spray gun within a closed pressurized circuit.
It is another object of the present invention to provide a spray gun cleaning system which, once activated, automatically and continuously cleans a spray gun without further user involvement.
It is a further object of the present invention to provide a spray gun cleaning system which can be used to clean a variety of different spray guns.
It is another object of the present invention to provide a spray gun cleaning system which can be used to clean a variety of paints, varnishes, stains, primers, or other application products used by spray guns.
These and other objects of the invention are provided by the spray gun cleaning system of the present invention. The system uses a separate cleaning fluid container which is substituted for the normal applied product container of the spray gun. The product feed tube of the spray gun is inserted into the cleaning fluid container, which is then sealably clamped to the spray cap of the spray gun. The container has a side opening, to which one end of a fluid hose is sealably attached. The other end of the hose is sealably attached to the nozzle portion of the spray gun. Pressurized air is discharged into the spray gun and this pressurization causes the cleaning fluid to circulate through the spray gun. As long as the pressurized air is discharged into the spray gun, cleaning fluid will automatically continue to circulate, without user involvement, through the sealed, closed circuit or path formed by the body of the spray gun, the fluid hose, the cleaning fluid container, and the feed tube. The cleaning system can thus automatically be allowed to operate as long as the user desires, in order to thoroughly clean the spray gun.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The spray gun cleaning system device itself, however, both as to its design, construction, and use, together with additional features and advantages thereof, are best understood upon review of the following detailed description with reference to the accompanying drawings.